HRS diagnostic criteria consist of (1) an increase in the serum creatinine level to greater than 1.5 g/dL (132.6 µmol/L) over days to weeks, (2) lack of response to an albumin challenge of 1 g/kg/d for 2 days, and (3) the absence of shock, nephrotoxic drugs, active urine sediment, proteinuria greater than 500 mg/d, and ultrasound evidence of parenchymal kidney disease or obstruction.